These Moths Follow the Stars
Scientists have discovered that the bogong moth finds its way by following the stars in the night sky.

© ssstocker/stock.adobe.com; Photo illustration Encyclopædia Britannica, Inc.
Could you find your way on a long journey using only the stars? Some humans and birds can. But scientists recently learned that the bogong moth also has this ability—and they’re surprised, considering that the moth’s brain is smaller than a grain of rice!
Every spring, Australia’s bogong moths escape the heat by migrating (traveling) 620 miles (1,000 kilometers) south. Settling in a mountain range called the Australian Alps, they take shelter in cool caves and stay there all summer.
Scientists noted that each generation of moths goes to the Australian Alps without ever having been there before. They wondered how the moths found their way. Some migrating animals use Earth’s magnetic field (our planet’s built-in compass) to sense which direction they’re facing. Others use the stars. Do bogong moths use either of these methods?

© Andrew/stock.adobe.com
A bogong moth
Eric Warrant, head of the Division of Sensory Biology at Lung University in Sweden, wanted to find out. He and other scientists created a flight simulator—a device that would make the moths think they were taking a long-distance flight. The scientists were able to use the simulator to recreate a night sky but block Earth’s magnetic field. They placed bogong moths into the simulator and took note of where the moths flew.
When the simulator showed the stars in the correct places, the moths flew in the right direction. But when the scientists changed the locations of the stars, the moths got confused and flew the wrong way. Scientists concluded that the moths rely on the stars to guide them when they migrate.
“It is an act of true navigation,” Warrant told CNN. “They’re able to use the stars as a compass to find a specific geographic direction to navigate.”
Migrating birds use both the stars and Earth’s magnetic field to migrate. But the bogong moth is the first invertebrate (animal without a backbone) known to use the stars to travel long distances.
David Dreyer, one of the scientists who took part in the study, says he’s impressed with the moths.
“It’s remarkable that an animal with such a tiny brain can actually do this,” Dreyer told the Associated Press.